High voltage bushing



April 26, 1960 H. F. KOLLINGER HIGH VOLTAGE BUSHING Filed Feb. 24, 1956INKENTOR. l eflz glfa/fin aen ATTORNEY;

United States Patent O i HIGH VOLTAGE BUSHING Henry F. Kollinger, BayCity, Mich., assignor to Kuhlman Electric Company, Bay City, Mich, acorporation of Michigan Application February 24, 1956, Serial No.567,664 4 Claims. (Cl. 174-145) This invention relates to transformerbushings and the like, and more particularly to a high voltage bushingprovided with means for covering and shielding the live parts againstshort circuits and a consequent disruption of service.

One of the prime objects of the invention is to design a high voltagebushing which permits all live connections to be made without the use oftools of any kind.

Another of the prime objects of the invention is to design a highvoltage bushing provided with an enclosed conductor clamp with a capserving as a shield to completely shield and cover electrically chargedparts of the clamp from accidental contact by the operator, animals ofall kinds, birds, falling branches and similar hazards which could causegrounds and short circuits causing service interruptions on adistributing system.

A further object is to design a high voltage bushing which affordssafety, convenience and speed in handling high voltage connections ontransformers, and which can be easily and quickly mounted in position.

Still a further object is to provide a bushing including an insulatedknob or cap resistant to weather and shock and which forms a rain-shedover the upper end of the bushing body in open, closed, or intermediateposition of the conductor clamp.

A further object still is to design a high voltage bushing provided witha plurality of circumferentially spaced radial openings to accommodatelive wires from either side, and also to permit excess voltage sparkoverto a lightning arrestor or other external device.

With the above and other objects in view, the present invention consistsin the combination and arrangement of parts, hereinafter more fullydescribed, illustrated in the accompanying drawing, and moreparticularly pointed out in the appended claims, it being understoodthat changes may be made in the form, size, proportion and minor detailsof construction without departing from the spirit, or sacrificing any ofthe advantages of the invention.

In the drawings:

Fig. 1 is a part sectional side elevational view showing my high voltagebushing.

Fig. 2 is a transverse sectional View taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary side elevational view showing the bushingmounted on a transformer tank cover.

Fig. 4 is a top plan view of the bushing.

Fig. 5 is a fragmentary part sectional side elevational view taken online 5-5 of Fig. 2.

Referring now more specifically to the drawing in which I have shown thepreferred embodiment of my invention. The letter B indicates the bushingproper which comprises a bushing body 8 formed of porcelain or otherinsulating material, provided with a plurality of corrugations 9 toprovide for creepage and centrally cored as at 10 to accommodate a cableterminal 11 which bears on a washer 12, and a lead wire 13 leads fromthe trans- 2,934,593 Patented Apr. 26,1960

ice

former (not shown), housed in tank T, to the threaded cable terminal 11above referred to.

The upper end of the bushing B terminates in an open top, generallycup-shaped housing section 14 in which a suitable terminal clampmechanism C is mounted, the clamp body being formed with an enlargedflange or face section 15 intermediate its length, with a cylindricaldepending section 16 extending into the core 10, said section beingbored and threaded as at 17 to accommodate a screw 18 extending throughterminal 11 to secure the upper end of the lead wire 13 in the usualmanner, and a corprene gasket 19 is provided between the flange 15 andthe upper end of the cored passage 10 i.e. at the bottom of the housing14, to prevent oil leakage at this point.

The terminal clamp includes a laterally projecting leg or terminal 20and a centrally disposed vertical opening or slot 21, the upper end ofsaid clamp being bored and threaded as at 22, and a centrally boredpressure screw 23 is threaded therein, said bore terminating in areduced opening 24 adapted to revolubly accommodate the hub 25 of afollow bar or jaw I, the face of the bar being preferably knurled toprovide a firm gripping surface.

The upper end of the pressure screw is slotted as at 26, and a rubberinsulated knob or clamping head 27 is molded thereon, this knob beingsubstantially spherical in shape with a depending skirt 27a of a size totelescope over the upper open end of the housing and form a rainshed forsame in open, closed, or intermediate position, and in closed positionthe lower edge of the skirt clears the line conductor L entering thehousing.

A plurality of flutes 28 are formed in the knob 27 to provide a securegrip, and it will be obvious that by turning the knob the follow bar ofthe clamping mechanism will be raised or lowered thus freeing orsecuring the line connection L therein.

Oppositely disposed openings or gaps 2929 are cored in the side wall ofthe housing section 14, these gaps accommodating a live wire L fromeither side. An opening 30 is also formed in the side wall andaccommodates the laterally projecting terminal 20 above referred to forestablishing a fixed or adjustable gap to an external device such as alightning arrestor terminal or ground terminal (not shown).

I also wish to direct attention to the fact that the upper surface ofthe base part 15 is preferably crowned or pitched from the centertowards the openings 29, 30, to provide natural drainage of waterthrough the openings and the adjacent surface of the jaw J iscomplementally shaped as is shown in Figures 1 and 5.

The lower end or shank of the bushing body B extends into the tank Tthrough opening 31, said body including a shouldered section 32 whichbears on the cover 33 of tank T, and a preferably stamped plate 34 fitsover tl e shoulder 32 and bolts 36 are provided for securing theassembly to the cover 33 of the tank.

From the foregoing description it will be obvious that I have perfecteda very simple, safe, and convenient high voltage bushing for connectingline leads to transformers; which shields all live parts from animals,birds, etc., and which also permits line connections to be made withoutuse of tools.

What I claim is:

1. A high voltage bushing comprising a cored body member formed ofinsulating material and terminating at one end in an open-top, generallycup-shaped housing having a bottom and having at least one openingthrough a side thereof; an electrically conductive clamp body memberhaving a base seated on the bottom of said housing and having an openingtherein in register with said opening in said housing to receive anelectrical conductor, said base having a crowned surface sloping fromits center towards the bottom of said housing; current conducting meansconnected to the base of said clamp body member and extending into thecored body member to form a cable terminal; a knob member formed ofinsulating material threadedly mounted for movement on one of said bodymembers; an electrically conductive clamp element located in saidopening of said clamp body member and having a clamping surfacecomplementary to the crowned surface of said base; and means connectingsaid clamp element to said knob member, said clamp element being movablewith said knob member towards and away from said base so as selectivelyto clamp and unclamp an electrical conductor between said clamp elementand said base, said knob member forming a closure and rain shed for theopen top of said housing.

2. The construction set forth in claim 1 wherein said knob member ismounted on said clamp body member.

3. A high voltage bushing comprising a cored body member formed ofinsulating material and terminating at one end in an open-top, generallycup-shaped housing having a bottom and having aligned openings throughopposite sides; an electrically conductive clamp body member having abase seated in said housing and having an opening therein in alignmentwith said openings in said housing to enable an electrical conductor tobe received in the opening in said clamp body member from either side ofsaid housing, said base having a crowned surface sloping from its centertowards the bottom of said housing; electrically conductive meansconnected to the base of said clamp body member and extending into saidcored body member to form a cable terminal; a hemispherical knob memberformed of insulating material threadedly mounted for movement on one ofsaid body members and having a depending skirt portion adapted totelescope over the top of said housing; an electrically conductive clampelement located in the opening of said clamp body member and having aclamping surface complementary to said crowned surface; and meansconnecting said clamp element to said knob member, said clamp elementbeing movable with said knob member towards and away from said base soas selectively to clamp and unclamp an electrical conductor between saidclamp element and said base, said knob member forming a closure and rainshed for the open top of said housing.

4. The construction set forth in claim 3 wherein said knob member ismounted on said clamp body member.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Publication: Pennsylvania Transformer Company advertisement,Electrical World, May 12, 1952, page 14.

